1. Field of the Invention
The disclosure relates generally to decoding methods and related decoding devices, and more particularly to image decoding methods and image decoding devices for decoding video images/pictures.
2. Description of the Related Art
Recently, portable devices, such as mobile or handheld devices, have become more and more technically advanced and multifunctional. For example, a mobile device may receive email messages, have an advanced address book management application, allow media playback, and have various other functions. Because of the conveniences of devices with multiple functions, the devices have become necessities of life. Due to the increasing capacity of mobile devices such as smart phones to support image and video specifications, such as video capture and playback capability supporting video quality up to 720P or even 1080P, a greater demand for embedded processors on mobile devices with coding and decoding capacity as far as high-specification video/picture contents are concerned.
For mobile devices with embedded processors, during performing the video image/picture decoding, partial decoded messages are typically first stored in an external storage device such as memory and then are read from the external storage device during subsequent processing for reconstruction of the video image or picture. To read these messages, frequent data reading/writing on an external storage device are often needed. As the operating frequency of the external storage device is lower, the data bandwidth size between the processor and external storage device often determines the speed. For example, when decoding 1080P high-definition video images, due to the large volume of the video image data, reading/writing on the external storage device is frequently needed, thus the considerably high reading/writing bandwidth ratios in proportion to the total bandwidth, for example, at the bandwidth of 1G bytes/sec or higher. Such high bandwidth requirement, however, may easily become a bottleneck of decoding speed enhancement.
It is therefore a desire to provide methods for efficiently reducing bandwidth required by the embedded processor to perform video images/pictures decoding.